Temporal Bone Fracture

Temporal bone fractures occur in about 14 to 22 percent of skull fractures, from blunt head trauma (motor vehicle collisions, falls, assaults, sports). They are often accompanied by intracranial injury (about 30 to 50 percent).

Classification is by the fracture line relative to the long axis of the petrous pyramid:

• Longitudinal (70 to 90 percent): from a temporoparietal blow, parallel to the axis, passing through the squamous temporal bone, external canal and tegmen tympani. It produces ossicular disruption, conductive hearing loss, tympanic membrane tears and bleeding, and facial nerve palsy in 10 to 20 percent, often delayed and incomplete.
• Transverse (10 to 30 percent): from a frontal or occipital blow, perpendicular to the axis, crossing the otic capsule, cochlea or vestibule. It produces profound sensorineural hearing loss, vertigo, nystagmus, and facial nerve palsy in 40 to 50 percent, often immediate and complete.
• Mixed or oblique.

Newer classification divides fractures into otic capsule sparing and otic capsule violating. The latter have higher rates of sensorineural loss, facial palsy (about 40 to 50 percent), cerebrospinal fluid leak and meningitis.

Complications include:

• facial nerve injury
• hearing loss (conductive, sensorineural, or mixed)
• vertigo and benign paroxysmal positional vertigo
• cerebrospinal fluid otorrhoea or rhinorrhoea, meningitis
• perilymph fistula
• vascular injury (carotid canal and jugular bulb: carotid dissection, pseudoaneurysm, thrombosis)
• cholesteatoma (post-traumatic)
• stenosis of the external ear canal

• Bleeding from the ear, haemotympanum, canal laceration and step off, tympanic membrane perforation.
• Battle sign (mastoid ecchymosis, delayed 24 to 48 hours), and periorbital ecchymosis (raccoon eyes) in associated skull base injury.
• Hearing loss, tinnitus, vertigo, nausea and nystagmus.
• Facial weakness (immediate or delayed onset, with grading from I to VI).
• Clear fluid otorrhoea or rhinorrhoea (cerebrospinal fluid, via the Eustachian tube).
• Neck or head signs of carotid injury (neurological deficits) and signs of intracranial injury (reduced consciousness).
• Often the patient is unable to cooperate because of head injury.

• Primary and secondary trauma survey, with cervical spine protection and assessment of neurological status, as per standard trauma care; otoscopic examination after the patient is stable (avoid syringing), with a tuning fork test (Weber and Rinne) when feasible.
• Facial nerve function examination and grading (House-Brackmann I to VI), and the time of onset noted (immediate versus delayed).
• High resolution CT of the temporal bone (0.5 to 0.625 mm slices, in axial and coronal planes), along with a CT brain: shows the fracture line, otic capsule integrity, ossicular disruption, fallopian canal involvement, tegmen defect, and carotid canal and sigmoid sinus injury.
• CT or magnetic resonance angiography when carotid canal or jugular bulb injury is suspected.
• Audiometry when the patient is stable (initially the bedside tuning fork test); electroneuronography (nerve excitability test, with a degeneration above 90 percent within 3 to 14 days indicating a need for surgical decompression) and electromyography for facial palsy.
• Beta-2 transferrin or beta trace protein in the fluid for confirmation of cerebrospinal fluid.

• Priority is life threatening injuries (airway, breathing, circulation, intracranial pressure) and a neurosurgical evaluation.
• Ear care: keep the ear dry, do not pack the canal, avoid syringing and ototic drops with a perforation unless there is infection, and avoid blowing the nose. Topical antibiotics (ciprofloxacin 0.3 percent, 4 drops twice daily for 7 days) when there is canal laceration and contamination.
• Hearing loss: haemotympanum resolves over 3 to 4 weeks. A conductive loss that persists beyond 3 months is evaluated for ossicular reconstruction or tympanoplasty (tympanotomy with ossicular repositioning or prosthesis placement, and tympanoplasty with temporalis fascia for a perforation).
• Sensorineural loss from labyrinthine fracture is usually permanent. Consider a hearing aid, bone anchored aid, or cochlear implant (if bilateral profound, performed early before labyrinthine ossification).
• A short course of high dose steroids for acute sensorineural loss (prednisolone 1 mg/kg daily for 7 to 14 days) is commonly used, with limited evidence in trauma.
• Facial nerve palsy:
  • Delayed onset or incomplete palsy: usually neurapraxia, treated conservatively with high dose corticosteroids (prednisolone 1 mg/kg daily, up to 60 to 80 mg, for 7 to 14 days, then tapered), eye protection (lubricating drops every 2 hours, ointment at night, taping or tarsorrhaphy), with excellent recovery in over 90 percent.
  • Immediate, complete palsy with CT showing fracture through the fallopian canal, or electroneuronography showing over 90 percent degeneration within 14 days: surgical exploration and decompression (middle cranial fossa, transmastoid or translabyrinthine route depending on hearing).
  • Repair (primary anastomosis or cable graft with the great auricular nerve) if the nerve is transected. The best results are with surgery within 2 to 3 weeks (no later than 3 months).
• Cerebrospinal fluid leak: bed rest with head elevation 30 degrees, avoiding straining, stool softeners (docusate 100 mg twice daily), and acetazolamide 250 mg three times a day (some centres). Most (about 85 percent) stop within 7 to 10 days.
• Persistent leak beyond 2 weeks requires lumbar drain (10 mL per hour for 3 to 5 days) and surgical repair (transmastoid or middle cranial fossa repair with fascia, fat, bone or cartilage).
• Prophylactic antibiotics are not recommended for cerebrospinal fluid leak. Give pneumococcal vaccination (conjugate then polysaccharide vaccine).
• Meningitis is treated with ceftriaxone 2 g every 12 hours plus vancomycin 15 to 20 mg/kg every 8 to 12 hours, with dexamethasone 0.15 mg/kg every 6 hours for 4 days.
• Vascular injury: carotid artery injury needs antithrombotic therapy (heparin, then anticoagulation or antiplatelet therapy) and endovascular repair by stent, in coordination with neurosurgery and vascular teams.
• Vertigo: vestibular suppressants for a short time (prochlorperazine 5 mg three times daily or cinnarizine 15 to 30 mg three times daily for 3 to 5 days), early mobilisation and vestibular rehabilitation, and Epley manoeuvre for benign positional vertigo.
• Canal stenosis and cholesteatoma: stenting and canalplasty, with follow up for cholesteatoma at 6 months and annually.
• Follow up: audiology at 3 months, facial nerve assessment serially, and imaging for complications.